1. Field of the Invention
This invention relates to a novel ester compound and a liquid crystal composition containing the same.
2. Description of the Prior Art
Display elements utilizing liquid crystals have been generally used for watches, electric calculators, etc. These liquid crystal display elements utilize the optical anisotropy and the dielectric anisotropy of liquid crystal substances. The liquid crystal phases include nematic liquid crystal phase, smectic liquid crystal phase and cholesteric liquid crystal phase, and display elements utilizing nematic liquid crystal phase among these phases have most frequently been used in practice. These display elements include those of TN (twisted nematic) type, DS (dynamic scattering) type, guest-host type, DAP type, etc., corresponding to the electrooptical effect applied to liquid crystal displays, and the liquid crystal substances used for the respective display elements are preferred to be those which exhibit liquid crystal phases within as broad a temperature range as possible in the natural world. Many liquid crystal compounds are known, but at present, there is no single substance which satisfies such a condition, hence several kinds of liquid crystal substances or non-liquid substances have been mixed and the mixtures have been applied to practical uses. These substances have been required to be stable to moisture, light, heat, air, etc.
The mixtures of the liquid crystal substances, etc. as described above, i.e. liquid crystal compositions, have been required to have an elevated usable temperature range, i.e. the nematic temperature range as high as possible, and it has been required that when the compounds are added as a constituting component of the liquid crystal compounds thereto, the nematic phase-isotropic liquid phase transition point thereof is raised without elevating the viscosity thereof, and a liquid crystal composition containing the same.